1. Field of the Invention
The present invention relates to a color image communication device and a color image communication method to be used in a facsimile machine, a copy machine, a multifunction peripheral of these machines or the like.
2. Description of the Related Art
A color facsimile machine includes a color scanner, and transmits scanned color image data via a telephone line. The color facsimile machine of this type transmits image data according to the International Telecommunication Union-Telecommunications (ITU-T) Recommendation T.81. However, there is a limit as to the size of the color image data which can be transmitted. Therefore, there are problems that image data photographed by a digital camera cannot be transmitted by facsimile. This is due to the fact that the size of the data file of the digital camera or the like is designated purely by the number of pixels (number of dots for length X width), and not by the number of pixels calculated from a printing size and the resolution which is handled in a conventional facsimile machine.
The image data photographed by a digital camera is generally expressed as Joint Photographic Experts Group (JPEG) image data of a standard (s) YCC color space (hereinafter referred to as the “sYCC-JPEG image data”). Meanwhile, the ITU-T Recommendation T.81 defines to transmit color image data as JPEG image data of a LAB color space of Computer-Integrated Enterprises (CIE) color system (hereinafter referred to as the “CIELAB-JPEG image data”).
Accordingly, a proposed device obtains function information (resolution, output color number) from a printer such that high quality color image data photographed by a digital camera in particular can be forwarded to the printer via a telephone line. When the obtained resolution or output color number of the printer is less than that of the device, the proposed device generates transmission image data in accordance with a lower resolution or output color number.
However, according to this technology, since transmission image data is generated in accordance with the function information of the printer, a construction for generating the data becomes complicated, and expensive. Moreover, when the resolution or the output color number of the proposed printer is less than that of the device, the proposed device generates the transmission image data in accordance with a lower resolution or output color number. It is not assumed to transmit the image data photographed by a digital camera without lowering the resolution or the output color number.
Next, a proposed facsimile machine is provided with a slot for a recording media used in a digital camera or the like. The proposed facsimile machine fetches once to a memory from the recording media, YCC-JPEG image data obtained by photographing by a digital camera. Then, the proposed facsimile machine deploys the YCC-JPEG image data as Red, Green, and Blue (RGB) image data in the memory of the proposed facsimile machine, and adds white pixels such that a width of the image data increases to a prescribed number of pixels. The proposed facsimile machine compresses the image data into LAB-JPEG image data again, and transmits the LAB-JPEG image data sequentially in accordance with the ITU-T Recommendation T.81.
According to this technology, the image data of a digital camera or the like is not transmitted from a facsimile machine as it is. In other words, the recording media (for example, Smart Media) is inserted in the slot of the proposed facsimile machine for loading the YCC-JPEG image data. The YCC-JPEG image data is converted into the RGB image data, and the white pixels are added. Then, the image data is compressed into LAB-JPEG image data, and transmitted. Therefore, there are problems that the proposed facsimile machine becomes complex and expensive.
Another proposed device includes a function for transmitting color information by a binary file transfer mode when communicating color information handled by a personal computer and color information handled by a digital camera. In addition, the proposed device includes a function for executing a facsimile communication in accordance with the ITU-T Recommendation T.81 when communicating color information handled by a personal computer and color information handled by a digital camera. When a recipient does not have a receiving function of a binary file transfer mode, the color information is converted into facsimile information based on the ITU-T Recommendation T.81, and the facsimile information is transmitted. When the recipient has the receiving function of the binary file transfer mode, the color information is transmitted by a binary file transfer mode.
According to this technology, when the recipient does not have the receiving function of the binary file transfer mode, the color information is converted into the facsimile information based on the ITU-T Recommendation T.81, and transmitted. Therefore, the image data of a digital camera or the like is not transmitted as it is. As a result, there are problems that a construction for converting the image becomes complicated and expensive.